SEATTLE -- Kyle Seager's first career grand slam was a historic one and gave Seattle a chance for an improbable victory. It also was one of the only clutch hits for the Mariners during a frustrating loss.
Seager's drive in the 14th inning capped a remarkable five-run rally, but the Chicago White Sox got RBI singles from Alejandro De Aza and Alex Rios two innings later and held on for a 7-5 victory on Wednesday.
The Mariners trailed 5-1 when Seager drove a 1-2 pitch from Addison Reed over the wall in right-center with two out for his eighth homer. It was the last hit of a remarkable inning.
According to the Mariners, with information from Elias Sports Bureau, Seager became the first player to hit a tying grand slam in extra innings, and no team had ever scored five or more runs in the 14th inning or later to tie a game. It also was the first game in major league history when each team scored five or more runs in the game when it was scoreless through the ninth.
But Seager's feat turned into a footnote due to numerous missed opportunities early in the game for Seattle.
"The most frustrating part is not executing. It was a great example for those guys," Seattle manager Eric Wedge said. "Really it was both teams were having issues with that today."
Rios had four hits and two RBIs for Chicago, which snapped an eight-game losing streak. Gordon Beckham also had four hits.
Seattle had a chance at its first sweep the season, but it left a runner at third in the first, second, fifth, sixth and 10th innings. Seager was thrown out at home to end the fourth while trying to score on Nick Franklin's fly ball.
The missed chances ruined another impressive outing from Hisashi Iwakuma, who pitched eight innings and retired his final 16 batters.
The Mariners were 3 for 16 with runners in scoring position after beginning the day with a .221 batting average in that category.
"(I'm) exhausted," Seattle shortstop Brendan Ryan said. "We had opportunities earlier we couldn't capitalize on."
After 13 innings of offensive futility, the sides combined for 10 runs and 10 hits in the 14th inning alone.
But the White Sox scored twice in the 16th against Hector Noesi (0-1), who gave up three runs and seven hits in three innings. De Aza drove in Beckham and eventually came around on an infield hit by Rios, who also singled home the first run of the game.
The two-run cushion proved to be enough for Reed (2-0) this time. He struck out Ryan on three pitches, and then got Endy Chavez and Jason Bay swinging to end it 5 hours and 42 minutes after the first pitch. It was too long for Chicago manager Robin Ventura, who had to leave early to catch a flight for his daughter's high school graduation.
"The whole pitching staff and the team really rallied around each other. It was really good to see," White Sox bench coach Mark Parent said.
Most of the action in the game took place in the 14th.
Rios singled in De Aza to break the scoring drought, and Chicago added another run on Casper Wells' infield single. Jeff Keppinger had a two-run single and Hector Gimenez doubled home a run as the White Sox sent 10 batters to the plate.
But Reed was shaky in the 14th, giving up four straight hits after Franklin popped out. The last of the four hits came from Chavez and scored Michael Saunders to make it 5-1.
Reed struck out Bay on a slider and had a 1-2 count on Seager when he left a fastball over the plate and the third baseman connected for his big shot.
The Mariners' dugout erupted and Seager wore a grin on his face as he rounded the bases. It was the first home run allowed this year by Reed.
"I don't think you can necessarily try to hit a home run off him. He's got pretty good stuff. He's their closer for a reason," Seager said. "Just try to put a good swing on the ball and not strike out."
Seattle was in a bad position when Noesi got knocked around in the 16th. The only other reliever left was closer Tom Wilhelmsen, who Wedge said before the game wouldn't be used.
"You don't score any runs for 13 innings, then you score 10 in one inning. That's baseball," Wedge said.
NOTES: Chicago announced RHP Jake Peavy has a non-displaced rib fracture on the left side of his chest and will be sidelined for approximately four to six weeks. The fracture was revealed in an MRI exam on Wednesday morning in Seattle. ... Seattle plans on having Michael Morse (quad) back in the lineup on Thursday, although Wedge has not decided if Morse will play first base or DH. ... Wednesday was the 13th game in Mariners history to be scoreless through nine innings.